Technical data

Manual VIPA System 200V Chapter 3 Digital input modules
HB97E - SM - Rev. 09/19 3-35
It is possible to specify a load value for the counter. After loading the
counter starts counting up res. down from this new value to the upper res.
lower limit value. After receiving a new counting pulse, the counter jumps to
the lower (counting up) res. upper limit (counting down) and starts the
counting again.
In the operation mode "Frequency Measurement" the load value is used to
define the time window of the measurement.
The load mechanism is controlled via the bit LOAD in the control byte.
In all counter modes, a continuous counter function is used as described in
the following paragraphs and as shown in figure.
If the counter reaches the upper count limit when counting up and a further
count pulse is received, the counter jumps to the lower count limit and
starts to add the count pulses again, meaning it counts continuously.
If the counter reaches the lower count limit when counting down and a
further count pulse is received, the counter jumps to the upper count limit
and continues to count down from there.
The count range in all modes is 0 to +4.294.967.295 and cannot be
changed. The counter starts to count at 0 when a complete restart (Power-
On Reset or VBUS-Reset) is executed on the module or the counter is
cleared by setting bit CLEAR in the control byte.
Counter value
Upper count
limit
Load value
0
Time
At the designation of maximum counter frequency, two types of indication
are distinguished:
• Maximum impulse frequency
The maximum impulse frequency is the maximum frequency the
adjacent signal may have, i.e. the maximum frequency at witch the
impulses arrive at the module. At this module the maximum impulse
frequency is 100Hz.
• Maximum counter frequency
The maximum counter frequency is the frequency at witch can be
internally counted to the maximum. At this module the maximum
impulse frequency is 400Hz.
Load value
Continuous
counting
Maximum
counter frequency